Contact lenses are roughly classified into hydrous contact lenses (including soft contact lenses) and non-hydrous contact lenses (including hard contact lenses and soft contact lenses), and hydrous contact lenses generally have an advantage that the lenses have a more satisfactory feeling of wearing than non-hydrous contact lenses.
However, since conventional hydrous contact lenses have high hydrability, there have been problems, for example, that lenses dry up quickly, and oxygen permeability is decreased.
Thus, silicone hydrogel contact lenses, which have high oxygen permeability while being less hydratable, have been developed, and in recent years, these constitute the mainstream of contact lenses. However, silicone hydrogels have a problem that since the silicone chains contained therein exhibit hydrophobicity, the feeling of wearing is not satisfactory, and lipids easily adhere thereto. In a case where the contact lenses are continuously used in that state while leaving these problems neglected, there is a risk that, for example, eyestrain, cloudiness, lowering of the visual acuity correction power, adverse effects on the cornea, may occur.
Under such circumstances, various cleaning solutions, storage solutions and coating solutions for contact lenses have been suggested for the purpose of eliminating those lipids adhering to the lens surface, enhancing the hydrophilicity of the lens surface, preventing the adhesion of lipids, or imparting lubricity.
For example, as the cleaning solutions for contact lenses, poly(oxyethylene)-poly(oxypropylene) block copolymers (poloxamer and poloxamine), which are nonionic surfactants, have been widely used heretofore (Patent Literature 1).